Nov 7, 2023 #1 J jts813 New Member View Badges Joined Oct 25, 2023 Messages 18 Reaction score 4 Location California Rating - 0% 0 0 0 I had a grey spot on rock. Then noticed it on sand as well. Had not heard of grey algae but seems like algae to me?
I had a grey spot on rock. Then noticed it on sand as well. Had not heard of grey algae but seems like algae to me?
Nov 7, 2023 #2 Dan_P 7500 Club Member View Badges Excellence Award R2R Research Joined Sep 21, 2018 Messages 7,571 Reaction score 7,962 Rating - 0% 0 0 0 More likely bacteria or a sponge
